During a surgical procedure it is often desirable to recover blood from the surgical wound and return it to the patient or harvest it for later use in blood salvaging procedures. Blood is typically recovered by suctioning it from the surgical wound, using a suction wand, through a tubing set into a collection reservoir. Suction wands generally aspirate both air and blood causing a turbulent flow in the suction wand and numerous blood to air interfaces as the blood is transported through the tubing set to the collection reservoir, blood oxygenator, blood salvaging device or the like. This turbulent flow in the suction wand coupled with blood transport having many blood to air interfaces, has been found to be a major source of blood trauma, particularly during open heart surgery. Furthermore, blood exposed to air may coagulate and form clots, thus, becoming unsuitable for reinfusion to the patient or for later use in blood salvaging procedures.
In the conventional system, this blood flow having many blood to air interfaces, must travel through a long tubing length before being collected in a collection reservoir, or processed by a blood oxygenator, blood salvage device or the like. Furthermore, in the conventional system the amount of suction applied to the suction wand typically remains constant throughout a surgical procedure. This constant suction does not account for the erratic and variable flow rate of patient blood losses during a surgical procedure; therefore, the same amount of suction is applied during low flow rates of patient blood losses as during high flow rates. Using a high amount of vacuum to suction blood during low flow rates may increase the amount of air aspirated into the tubing set along with patient blood. This may not only increase the turbulent blood flow, but may also increase the air to blood interface, thereby increasing the potential for blood trauma.
It is, therefore, desirable to reduce the turbulence of blood flow in blood salvaging procedures. It is also desirable to reduce the distance that salvaged blood must travel in contact with air. Further, it is desirable to reduce the air to blood interface in blood salvaging procedures.